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A comment on Writing Speed-of-Light Flash Attention for 5090 in CUDA C++. Parent comment

Re:Writing Speed-of-Light Flash Attention for 5090 in CUDA C++ by neilmovva on Saturday August 23, 2025 @02:52PM (#44998158)
Not really:

5090: 210 TF / $2k == 105 TF/$k

B200: 2250 TF / $40k == 56 TF/$k

Getting only 2x the FLOPs per dollar probably isn't worth the hassle of having to rack 10x as many GPUs, while having no NVLink.

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Re:Writing Speed-of-Light Flash Attention for 5090 in CUDA C++ by lossolo on Saturday August 23, 2025 @04:15PM (#44998778)
One of the reasons they removed NVLink from consumer cards (they supported it before). There’s also an issue with power consumption (1xB200 vs 10x5090)
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Re:Writing Speed-of-Light Flash Attention for 5090 in CUDA C++ by steinvakt2 on Saturday August 23, 2025 @08:04PM (#45000113)
Sure, but when spending 20x more, getting almost twice the compute per buck seems expected
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